Green Tea Extract in Preventing Cancer in Former and Current Heavy Smokers With Abnormal Sputum

DISEASE CHARACTERISTICS:

* Current smokers who have smoked at least 30 pack-years (e.g., 1 pack per day for 30 years or more) (part 1; completed March 22, 2006)
* Former smokers who have smoked at least 30 pack-years (part 2)

  * A former smoker is defined as one who has stopped smoking for one or more years
* Abnormal sputum score ≥ 0.25 by computer-assisted image analysis
* Exhaled carbon monoxide level \< 5 ppm (part 2 )
* Willing to take defined green tea catechin extract/placebo twice a day regularly
* No evidence of overt lung cancer

  * No carcinoma in situ or invasive cancer on bronchoscopy or abnormal spiral chest CT suspicious of lung cancer

PATIENT CHARACTERISTICS:

Inclusion criteria:

* ECOG performance status 0-1
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception
* Creatinine normal
* Bilirubin normal
* AST and ALT normal
* Alkaline phosphatase normal

Exclusion criteria:

* Chronic active hepatitis/liver cirrhosis
* Severe heart disease (e.g., unstable angina, chronic congestive heart failure, use of antiarrhythmic agents)
* Ongoing gastric ulcer
* Acute bronchitis or pneumonia within one month
* Known reaction to lidocaine, albuterol sulfate, midazolam hydrochloride, and/or alfentanil hydrochloride
* Known allergy to green tea and/or corn starch, gelatin, or other nonmedicinal ingredients
* Any medical condition, such as acute or chronic respiratory failure or bleeding disorder that, in the opinion of the investigator, could jeopardize the patient's safety during participation in the study
* Unwilling to have a bronchoscopy
* Unwilling to have a spiral chest CT

PRIOR CONCURRENT THERAPY:

* No more than 5 cups of tea a week
* No concurrent anticoagulant treatment such as warfarin or heparin
* No use of other natural health products containing green tea compounds